1. Technical Field
The present invention relates to image-forming systems furnished with: a printer, copier, or like image-forming unit; an image-capturing unit that transfers image information to the image-forming unit; and a document-feeding unit that feeds document original sheets to the capturing unit.
2. Description of the Related Art
Generally, image-forming systems that are composed of an imaging device (printer unit) that forms images on sheets, an image-capturing device (scanner unit) that supplies image data to the imaging unit, and a document-feeding unit (ADF unit) that feeds document-original sheets to the image-capturing apparatus, and that in the scanner unit capture images on document sheets fed from the ADF unit and form images in the printer unit are the widely known image-forming systems of this type.
For this sort of image-forming system, layout configurations—such as disclosed, for example, in Japanese Unexamined Pat. App. Pub. No. 2006-42003—wherein the scanner unit is installed above the printer unit and the ADF is installed above the scanner unit are known. In this patent reference a layout is disclosed in which the installation is stacked by turns upward by disposing the discharge tray over the printer housing, installing the scanner unit above the discharge tray, and then disposing the ADF unit over the scanner housing. This configuration is designed to make the installation space for the system overall smaller, and to improve its operability at the same time.
Openably mounting the scanner unit on the printer unit with hinge members, and openably mounting the ADF unit on the scanner unit with, again, hinge members is known. In this way openably joining each unit onto the printer housing makes it possible to rotate the overhead scanner upward when a need to clear open the area over the housing has arisen for maintenance purposes such as removing jammed paper or replacing parts. Likewise, when the upper part of the scanner housing is swung open, the ADF unit can be rotated upward on the hinges.
However, when the scanner unit is rotated around the hinge members, a problem arises in that the ADF unit disposed above the scanner unit is thereby also rotated (opened). For that reason, the above-cited patent reference proposes providing locking means between the scanner unit and the ADF unit to prohibit it from coming open due to the rotation of the ADF unit when the scanner unit is rotated upward. The locking means is configured to check the ADF from moving open on the hinges between the ADF unit and the scanner unit when the scanner unit is opened on the printer unit.
As described above, for implementations where above the printer unit, the scanner unit, and above it, the ADF unit, are respectively joined by hinges allowing them to open/close, locking mechanisms, as in the above-cited reference, that co-operate with the opening/closing action of the scanner unit to restrict the open/close moving of the ADF unit are known.
However, in the above-cited patent reference, the locking mechanism is disposed on the same side (in the embodiments, the rear side of the units) as the location where the hinges linking the scanner unit and ADF unit are disposed. The locking mechanism is configured to check the movement of the ADF unit opening by causing a lever (second rotating member 50) disposed on the scanner unit side to engage with a member (a stepped part 56) projecting from the ADF unit. Consequently, with the ADF unit in the locked state, when the front side is grasped to lift the ADF unit upward, an extremely large force (moment) is applied to the engaging portions of the locking mechanism (in other words, the engaging portions of the stepped part 56 and the second hook 52 of the second rotating member 50), which risks damaging the locking mechanism.